When dimensioning generators, current distributors and electrical lines in aircraft engineering, today dimensioning is predominantly according to the maximum current-power requirement of the connected electrical consumers. This means that generators for the supply of current to the aircraft, current distributors and electrical lines are dimensioned such that all electrical devices present on board can be supplied with the maximum current-power requirement, if need be concurrently.
In this arrangement, the sum of the total peak-current consumption is taken into account. For example, the current distribution network is dimensioned such that concurrent uptake of the peak current of the individual devices is provided for, although the probability of such concurrent uptake is low. As a result of this, disadvantageously, non-used overcapacity is taken into account in the planning of such electrical systems for aircraft, as a result of which the costs of producing an aircraft increase.
By way of intelligent control systems, according to a specified logic, consumers may be broken down into priority classes and may be switched on or off according to the generator loads at the time and the flight phases. For example, when loading or boarding an aircraft it is more important that the lighting of information signs or the drive of a lift device is switched on, than flight current required for operating automatic coffee machines or microwave ovens for heating meals for passengers, for example. While dividing these electrical devices into priority classes in dimensioning the current distribution systems makes it possible to work out the concurrent use of certain device classes, it does however not prevent dimensioning occurring on the basis of the peak-load requirement of the individual devices.
A great many electrical consumers are frequently only temporarily switched on, for example, lift drives for a trolley lift or the electrical lift drive for bins or hat-rack bins. The switch-on duration of such consumers often ranges from only a few seconds to a few minutes. If the allocation of such devices, for example, takes place by means of the above-mentioned priority classes, it may not be possible to activate a consumer when required, because its activation is not provided for in this particular flight phase.